Acquisition and Equity-Method Investment - Change in the Carrying Value of Equity Method Investment (Details) - USD ($) $ in Millions		3 Months Ended					9 Months Ended
		Sep. 29, 2024		Jun. 30, 2024	Oct. 01, 2023		Sep. 29, 2024		Oct. 01, 2023
Schedule of Changes in Carrying Value of Investments [Roll Forward]
Beginning carrying value reported in Equity-method investments							$ 11,637
Ending carrying value reported in Equity-method investments		$ 8,582					8,582
Haleon [Member]
Schedule of Changes in Carrying Value of Investments [Roll Forward]
Beginning carrying value reported in Equity-method investments		7,796			$ 11,228		11,451		$ 10,824
Carrying value of shares sold		0			0		(3,312)		0
Dividends		(55)			(65)		(212)		(154)
Currency translation adjustments and other	[1]	471			(446)		341		(172)
Basis difference adjustments and amortization	[2],[3]	10			0		(91)		(1)
Pfizer share of Haleon investee capital transaction		46	[2],[4]	$ (91)	0	[2],[4]	(44)	[2],[4]	0	[2],[4]
Pfizer share of Haleon earnings	[2]	88			122		224		341
Ending carrying value reported in Equity-method investments		$ 8,356		$ 7,796	$ 10,838		$ 8,356		$ 10,838

[1] See Note 6.

[2] Included in Other (income)/deductions––net.

[3] Adjustments in the nine months ended September 29, 2024 include (i) the impact of Haleon’s brand divestitures and impairments of intangible assets and (ii) changes in Haleon’s tax rates on intangible asset-related deferred tax liabilities.

[4] The nine months ended September 29, 2024 includes (i) a decrease of $91 million recorded in the second quarter of 2024 for Pfizer’s share of an investee capital transaction recognized by Haleon for treasury stock Haleon purchased in the first quarter of 2024 and (ii) an adjustment of $46 million recorded in the third quarter of 2024 for the impact of the reduction in Pfizer’s ownership from approximately 32% to approximately 23% as applied to dividends with a record date in the first quarter of 2024, which were recognized in Haleon’s second quarter 2024 financial statements.